Voltaic Solar Bloghttps://www.voltaicsystems.com/blog
Solar Guide and DIY Solar TutorialsWed, 21 Feb 2018 20:33:23 +0000en-UShourly1https://wordpress.org/?v=4.9.4https://www.voltaicsystems.com/blog/wp-content/uploads/2017/02/voltaic_ico_transparent.pngVoltaic Solar Bloghttps://www.voltaicsystems.com/blog
3232Lithium Ion Charge Controller Performancehttps://www.voltaicsystems.com/blog/lithium-ion-charge-controller/
https://www.voltaicsystems.com/blog/lithium-ion-charge-controller/#respondFri, 16 Feb 2018 17:37:27 +0000https://www.voltaicsystems.com/blog/?p=9619In this article we evaluate three popular lithium ion solar charge controllers, with and without MPPT, and compare their performance with a variety of different size panels in different lighting conditions. Evaluation of Three Lithium Ion Solar Charge Controllers Charging batteries or powering devices through a solar panel is very different than having a continuous […]

]]>In this article we evaluate three popular lithium ion solar charge controllers, with and without MPPT, and compare their performance with a variety of different size panels in different lighting conditions.

Evaluation of Three Lithium Ion Solar Charge Controllers

Charging batteries or powering devices through a solar panel is very different than having a continuous supply of DC current, such as through an AC adapter. Solar panels’ power output (Voltage X Current) vary based on the amount of solar intensity and temperature. We visualize this characteristic of each solar panel through something called an IV curve, which shows how much current a solar panel can provide at a specific voltage and specific solar intensity (irradiance). Take the graphic below for example:

This is a generic set of IV curves for one panel, where the colored lines are the different solar intensities. From an IV curve, we can derive the power output (since P = IV) and the maximum power of a solar panel is right at the bend in the IV curve, marked by a star on the graph. This is the point where the system should operate to get the most out of the solar panel. MPPT stands for maximum power point tracker and as the name suggests, its goal is to track the MPP in all light conditions because it shifts with irradiance – the black line.

Adafruit vs. Sparkfun Sunny Buddy vs. TI MPPT

The Adafruit Solar Lipoly Charger doesn’t have MPPT, while both the other charge controllers tested do. Adafruit’s design notes give some documentation on why: higher cost, comparable efficiency, etc. Here is a comparison chart of some of their relevant specifications:

Test Setup for Lithium Solar Charge Controllers

The experiment has two variables: irradiance and panel size. Voltaic’s 1, 2, 3½ , 6, and 9 Watt panels were used. Each panel is connected through a USB multimeter (we used the YZX ZY1270 and ZY1266) into the solar charge controller, then through another USB multimeter and into a 3.7V lithium polymer cell. We measured the current and voltage in each setup to see how each solar charge controller performs with a specific panel size and under a specific light condition. From these measurements, we can calculate the power output and the efficiency of the module.

Voltaic has a full range of solar panels for prototyping and deployment.

Results

In the tests in bright light, the TI module outperforms the rest. However, it is important to keep in mind that past the 3½W panel, the Adafruit Over the Shelf (OTS) and Sunny Buddy hit their programmed current limits and cannot provide any more power. Similarly, the modified Adafruit board hits its 1A limit with the 9W panel. If the current limit for the Adafruit is enhanced to 1A, its power output is doubled at the 9W panel. It’s important to keep in mind the limitations embedded into these boards when comparing them to one another.

In medium light, the TI module still performs well, but it’s interesting to note how the two different Adafruit chargers vary in these two situations. In bright light, the modified version (1A max) beats the off-the-shelf (500mA max), while in lower light it’s reversed. The current limit is no longer a factor and so this is a fair light condition to test the controllers in. The Adafruit and Sunny Buddy have comparable performance.

In both situations, note how the trend among the panels remains consistent, with all the power outputs varying in consistent ratios from panel to panel.

The 1, 2, and 3½ Watt panel results from the dim-light graph are unreliable because the power output was so low that the USB multimeter readings were out of their accuracy range. Although current is likely flowing into the battery, the amount was hard to measure as the USB multimeters themselves draw current. We estimate that the input to the battery was less than 6 mA. In this additional low light condition, the Adafruit OTS continues to do well as the current limit never comes into play. The Sunny Buddy performed more poorly than expected, but it’s a possibility that the potentiometer should’ve been adjusted in the dim-light setting to account for the lower MPP voltage.

Solar Charge Controller Recommendations

Adafruit Solar Lipoly Charger

The Adafruit is the cheapest, but it does have certain modifications you can make to improve the efficiency and power output. One limitation of the board is that it has a set battery float voltage, at 4.5 volts. This is certainly enough to charge most single-cell lithium-polymer batteries, but it isn’t optimal in all situations. Secondly, there is a current limit that is 500mA off the shelf, but modifiable up to 1A if a 2kΩ resistor is connected across the ‘PROG’ pins. Because of the current limitations, it restricts the power output and efficiency of the Adafruit board in situations with greater irradiance and/or larger panels. Yet at the same time, we see that modifying it reduces its power output in lower light conditions.

Because of its low price, consistent power output, and clear documentation, the Adafruit Solar Lipoly charger is a strong choice for those looking for an easy off-the-shelf solar charge controller that needs little to no modifications and is an all-around performer.

Sparkfun Sunny Buddy

The Sunny Buddy has similar limitations to the Adafruit board. Its default current limit is at 450mA, but it can go up to 2A. The pro of the Sunny Buddy is that there is an adjustable voltage input regulation setting which can be changed by turning an on-board potentiometer. Essentially, the MPPT point is set manually beforehand and the hook-up guide shows how to do this. This customization is a form of MPPT tracking but as the Adafruit design notes stated, it didn’t result in an increase in performance, just in cost. It’s worth noting that also similar to the Adafruit design it has a 4.4V battery float voltage.

The Sunny Buddy has a better power management and battery charging chip, the LT3652. The board is also mostly unpopulated, allowing for more custom connections beyond the barrel jack and JST connectors. For someone willing to delve into the LT3652 datasheet, this is a strong board because of its larger range of features, such as termination schemes and fault detection.

TI bq24650EVM

Finally we have the TI board, which allows modifications on both the input and output voltage sides. It has the most technical freedom since it is an evaluation module, though using it can be cumbersome. It requires diving into the datasheet to figure out which resistors to use for which panel voltage or battery float voltage, and then connecting them onto the evaluation module. However, the results are remarkable, with the highest power output in almost all situations. The benefit of this board, besides the obvious, is its flexibility, allowing a range of solar panels and the ability to charge many battery types, even multiple cells in series. It has a high efficiency and a whopping 8A maximum current.

The bq24650EVM (evaluation module) is not for beginners. Despite its stellar power output and its ability to accommodate almost all solar charging combinations, it is both expensive and complex.

Conclusion

Powering outdoor electronics project through solar isn’t always easy, but with one of these solar charge controllers it’s definitely easier. Combined with a good panel, a strong solar-powered system could be optimized to achieve maximum power in a variety of light conditions and thus increase its longevity and reliability. We hope that this article has been informative to both newcomers and veterans of solar-powered projects, and good luck!

If you want to talk to a Voltaic expert about continuously powering sensors or other IoT devices from solar power, schedule an IoT Consultation here.

Charging a digital camera, even professional level DSLRs, when you’re not near an outlet is surprisingly easy and fast. Follow our guide below to learn how to efficiently charge your digital camera battery from USB and get shooting.

Step 1: Find Your Camera Battery Model Number

Remove the battery from your digital camera and located the model number. The image below shows that this Canon battery is a LP-E8 model (circled in the red).

Step 2: Find the Matching USB Camera Cradle

Head over to our USB camera adapters section and look up your cradle by brand. If you don’t see your camera battery model listed, contact our team and we’ll be happy to help you find the one you need.

Step 3: Connect Camera Cradle to Battery Pack or Solar Panel

You can use any USB battery pack to charge the camera cradles above. These are also compatible with solar panels that have a built-in USB output like our Arc 10W Solar Charger. Voltaic battery packs are optimized to charge efficiently from solar and charge and discharge at the same time. We recommend charging from the 2 Amp USB port on our V44 USB Battery and V72 Laptop Battery when charging batteries multiple times.

How Well Does Charging Cameras from USB Work?

When using the 2A output, we can charge camera batteries quickly, but not quite as fast as from the wall. The output on our adapters is 800mA vs 1.2A on the Canon charger for the LP-E6 (our most popular selling charger). So we’re charging 2/3rds as fast as you would at home.

Note, some USB camera adapters available on Amazon output 400mA. These adapters will charge the camera batteries half as fast.

Wait, I Thought Camera Batteries Had Higher Voltage Than USB

It is true. Most camera batteries in DSLR and full frame mirrorless cameras are 7.4V and USB is only 5V. To charge the battery, the camera adapter boosts the voltage from 5 to 8.4. At that higher voltage, the USB cradle is able to charge the 7.4 Volt camera battery.

]]>https://www.voltaicsystems.com/blog/charge-camera-battery-usb/feed/0Low Cost Air Sensor Calibration and Evaluationhttps://www.voltaicsystems.com/blog/sensor-calibration/
https://www.voltaicsystems.com/blog/sensor-calibration/#respondThu, 01 Feb 2018 20:21:14 +0000https://www.voltaicsystems.com/blog/?p=9448Deploying Low Cost Air Sensors As more and more low cost sensors appear, the reach and applications can be tantalizing. The question that crops up is whether the sensors are any good and can provide reliable data. Led by David Hagan, researchers at MIT, Virginia Tech and Hawaii State Department of Health recently compared nine […]

As more and more low cost sensors appear, the reach and applications can be tantalizing. The question that crops up is whether the sensors are any good and can provide reliable data. Led by David Hagan, researchers at MIT, Virginia Tech and Hawaii State Department of Health recently compared nine custom built sulfur dioxide sensors against regulatory grade sensors operated by the Hawaii Department of Health. The paper is published in Atmospheric Measurement Techniques here.

If you’re interested in deploying large sets of electrochemical sensors, it is worth reading how they use a hybrid algorithm that allows extrapolation beyond the training set of data.

The system consisted of an Alphasense SO2-B4 sensor, RHT sensor and a DC fan. The power was provided by a Voltaic 9 Watt solar panel and 4,000mAh battery. The system sent data to the researchers via a Particle 3G modem.

Sensor schematic – from paper in Atmospheric Measurement Techniques

The basic advantage of low cost air sensors is that you can deploy more. If you’re looking at measuring air quality in New York City, for example, a few sensors won’t provide the detail needed to identify where and when the quality of air degrades. The newer sensors also tend to be smaller which allows them to be mobile or seamlessly integrated into the landscape. However, according to Hagan, “accurate calibration of such sensors poses a major challenge.”

Air Sensor Setup

Here are the sensors during setup. This is the same location as the higher end sensors.

]]>https://www.voltaicsystems.com/blog/sensor-calibration/feed/0Lithium Battery Policy By Airlinehttps://www.voltaicsystems.com/blog/lithium-battery-policy-airline/
https://www.voltaicsystems.com/blog/lithium-battery-policy-airline/#respondWed, 24 Jan 2018 20:37:01 +0000https://www.voltaicsystems.com/blog/?p=9378Lithium Battery Policy for Domestic and International Flights Can I bring my batteries on the plane? Lithium batteries are allowed on planes, but the rules vary by airline. We look at each major airline and summarize their lithium battery policy. These policies change, so if you’re planning on carrying on a lot of gear, please […]

Can I bring my batteries on the plane? Lithium batteries are allowed on planes, but the rules vary by airline. We look at each major airline and summarize their lithium battery policy. These policies change, so if you’re planning on carrying on a lot of gear, please double check with the airline.

Voltaic Systems’ battery packs have all passed the UN 38.3 test required by the International Air Transport Association (IATA). In addition, they have the following safety protections: short circuit, over charge, over discharge, over current and over temperature. Batteries contained in our solar backpacks are all easily removable if you need to check them. View our Traveling with Solar Guide for more information.

A couple other common recommendations:
– tape or cover the terminals on loose batteries to prevent them from short circuiting
– don’t travel with damaged batteries

How do I know how large my battery is in Watt hours or Lithium Content?

The airlines break down batteries into sizes either by their “Watt hours” (Wh) or, less commonly, grams of lithium content. Almost all phones, tablets and laptops will be considered in the small category and well less than 100 Wh. If the battery is removable, pull it out and the capacity will most likely be listed on the battery. If not, you can calculate it by multiplying the Voltage by the mAh and divide by 1,000.

To get over 100 Wh, you are either dealing with a battery on a commercial grade video camera or a really large power bank. All power banks are required to have the capacity listed on the surface of the product.

If your airline breaks down batteries by their lithium content, 8 grams is equivalent to a 100 Wh lithium ion battery.

]]>https://www.voltaicsystems.com/blog/lithium-battery-policy-airline/feed/0How to Charge a DJI Spark from an External Battery Packhttps://www.voltaicsystems.com/blog/charging-dji-spark-battery-pack/
https://www.voltaicsystems.com/blog/charging-dji-spark-battery-pack/#respondThu, 18 Jan 2018 20:48:41 +0000https://www.voltaicsystems.com/blog/?p=9392How to Charge a DJI Spark Offgrid The DJI Spark is DJI’s smallest drone offering. If you are offgrid, there are two ways to charge a DJI Spark from an external battery pack or power bank. Option 1: Charge direct from an external battery pack using the USB Cable Connect the USB cable to the […]

The DJI Spark is DJI’s smallest drone offering. If you are offgrid, there are two ways to charge a DJI Spark from an external battery pack or power bank.

Option 1: Charge direct from an external battery pack using the USB Cable

Its straightforward to charge the Spark from USB.

Connect the USB cable to the USB output on a battery pack. We saw the Spark taking almost 10 Watts (1.95A at 4.82V) from our V72 and V44 battery packs. Since the battery is 16.87 Wh, that translates to about a 2 hours charge time to 90% full. Note, there is loss going from the chemical energy in one battery pack to stored chemical energy in the DJI battery pack so if you had a 17 Watt hour battery pack, you’ll probably get about 70-75% of a full charge on the Spark battery.

DJI Spark from USB Port Charges at ~ 10 Watts

Option 2: Hack the Charging Hub

Warning – you will void the warranty and potentially create an unsafe charging solution. Only do this if you are skilled with electronics and thoroughly test the safety of the system.

With a 16 minute flight time, we often want to charge batteries in the background while we fly. To try to get the hub to work from DC power, we connected the 12V output of our V72 battery directly to the charging hub, bypassing the AC block. This system quite frankly doesn’t work that well. It only charges one Spark battery at a time and draws almost 24 Watts (1.9A at 12V). Not all that power is flowing into the battery, so it must be wasted by the hub.

Charging the Spark battery through a hacked cable directly into the Voltaic laptop battery.

Here was our setup:
1. Cut the cord on the charging station and separated the center wire (positive) from the outer shell (negative). Be careful not to leave any stray strands that can cause a short circuit
2. Cut our laptop output cable in half and exposed the positive (red) and negative (black) wires
3. Solder positive to positive, negative to negative and cover with heat shrink tubing

Connect positive to positive, negative to negative

DJI Charging Hub with 5.5X2.5mm Cable Attached

Hopefully some third party options for charging Spark batteries will open up, but charging directly into the Spark is the most efficient for now.

Why Voltaic Systems Battery Packs Work Best

There are a lot of battery packs out there, but most of them charge horribly from solar power and a lot of them don’t charge and discharge at the same time. If you’re interested in charging your DJI Spark batteries in the field at the same time you charge your phone or laptop, our batteries are specifically designed to do that well.

]]>https://www.voltaicsystems.com/blog/charging-dji-spark-battery-pack/feed/0How to Keep Camera Batteries Warm in Cold Weatherhttps://www.voltaicsystems.com/blog/keep-camera-batteries-warm-cold-weather/
https://www.voltaicsystems.com/blog/keep-camera-batteries-warm-cold-weather/#respondTue, 16 Jan 2018 18:41:17 +0000https://www.voltaicsystems.com/blog/?p=9379How To: Keep Camera Batteries Warm Keeping camera batteries warm in cold weather will increase the number of photos you can take. We asked several of our photographers who work in cold places how they maintain temperature and a charge on their batteries. Batteries, especially the rechargeable Lithium Ion batteries used in cameras, show a […]

Keeping camera batteries warm in cold weather will increase the number of photos you can take. We asked several of our photographers who work in cold places how they maintain temperature and a charge on their batteries. Batteries, especially the rechargeable Lithium Ion batteries used in cameras, show a remarkable decrease in capacity when used in below freezing temperatures.

Know Your Camera in the Cold

Different cameras may exhibit different cold weather performance. Brian Threlkeld, a Portland Maine based photographer, has experienced times where he has put in a fresh battery in his Sony a7ii and watched it go to 5% after a few clicks of the shutter. Knowing this before a big shoot, he can be better prepared.

Brian captures a team member during their winter circumnavigation around Mt Katahdin in Maine.

Bring More Batteries

Joe Klementovich (photo credit for top image!) is a photographer based is New Hampshire and recommends simply bringing more batteries than usual because they eventually “drain faster no matter how warm you store them.”

Use a Fanny Pack under Outer Layers

Joe was recently photographing in -10 degree days around Mt. Washington. His trick is to use a small fanny pack next to his body and underneath his down jacket or fleece layer. He keeps drone and DSLR batteries there instead of a pocket as it is easier to locate and is a consistent place to find the batteries no matter what layer he has on.

A great photo by Joe Klementovich, but we recommend charging inside a pocket or sleeping bag for maximum power transfer in cold weather.

Use the Inside Pocket

If you don’t have a fanny pack, be sure to use an inside instead of an exterior pocket. Brian keeps his spare batteries close to his core and swaps them into the camera whenever one drops to low. After a few minutes next to his body, the battery that read 5% is ready to use again. “It’s kind of like I’m playing a trick on my camera, or the other way around.”

Bruce Wilson, a videographer from Utah, also favors an inside pocket. He says, “camera batteries die quickly in the cold, they could easily go from 20% power to zero in seconds.” He adds that prior to starting the hike, he puts the batteries near the car heater so that they start off warm.

Recharge at Night in Camp

Brian doesn’t bother recharging batteries during the day. He insteads recharges them in his sleeping bag of his V44 or V72 battery pack. The batteries then spend the night inside a stuff sack inside the sleeping bag. “That way when I wake up in the morning, I can put a warm battery in and snag those authentic camp shots of people getting out of their down cocoons without missing a beat.”

Justin Packshaw had similar tactics in Antarctica where the average temp was -34 Celsius. They recharged their cameras, Phantom 4 drone and sat phone at night inside the sleeping bag.

Charging drones, phones and communications gear in Antarctica

Hand Warmers?

No photographers we talked with used the chemical hand warmers for fear of damaging the batteries.

Any other tips for cold weather? Let us know in the comments. Need a photographer that thrives in the cold? Talk to Joe, Brian or Bruce.

]]>https://www.voltaicsystems.com/blog/keep-camera-batteries-warm-cold-weather/feed/0Solar Panel Tariffs Will Affect Small Solar Panels Toohttps://www.voltaicsystems.com/blog/solar-panel-tariffs-affect-small-solar-panels/
https://www.voltaicsystems.com/blog/solar-panel-tariffs-affect-small-solar-panels/#respondFri, 12 Jan 2018 20:53:11 +0000https://www.voltaicsystems.com/blog/?p=9373The Trump Administration has imposed 30% tariffs on solar panels made outside of the United States. Those tariffs are targeting large modules for commercial and household installations, but they will sweep up Voltaic’s small solar panels and solar backpacks as well. Voltaic solar panels are a far cry from “dumping”. Our 2 Watt panel sells […]

]]>The Trump Administration has imposed 30% tariffs on solar panels made outside of the United States. Those tariffs are targeting large modules for commercial and household installations, but they will sweep up Voltaic’s small solar panels and solar backpacks as well.

Voltaic solar panels are a far cry from “dumping”. Our 2 Watt panel sells for $29 retail, almost $15 a Watt vs close to $1 a Watt for a commercial panel. Customers pay that money because they know they get a high quality product that will last outside in rough conditions for ten plus years. Neither are these modules harming the companies who brought the case, SolarWorld and Suniva. In fact, SolarWorld is the dominant supplier of cells that we use in our panels.

Our costs will increase and we will need to pass some of that onto our customers. This will likely decrease our sales volume and limit our ability to hire new staff to design and assemble systems.

They argue that the increase in module costs will hurt the solar industry in the US, which employs 260,000 people across 50 states. They will also increase costs to homeowners who are looking to reduce their monthly energy bills.

]]>https://www.voltaicsystems.com/blog/solar-panel-tariffs-affect-small-solar-panels/feed/0Ring Cam – Choosing a Better Solar Panelhttps://www.voltaicsystems.com/blog/ring-cam-choosing-a-better-solar-panel/
https://www.voltaicsystems.com/blog/ring-cam-choosing-a-better-solar-panel/#commentsSat, 06 Jan 2018 19:02:12 +0000https://www.voltaicsystems.com/blog/?p=9167Ring Solar Charger by Voltaic Ring has been making smart doorbells, WiFi cameras, and other home automation devices since 2012. We decided to test the Ring Stick Up Cam’s performance with our high performance solar panels to compare against the 2 Watt Ring solar charger that is available on their website. The goal is to […]

Ring has been making smart doorbells, WiFi cameras, and other home automation devices since 2012. We decided to test the Ring Stick Up Cam’s performance with our high performance solar panels to compare against the 2 Watt Ring solar charger that is available on their website. The goal is to reduce the probability that your Ring’s internal 19.24 watt-hour battery goes flat.

If you have the Blink, Blink XT, Arlo Go, Arlo Pro, or the Arlo Pro 2, you will also be able to stay charged up from the solar panels recommended below. Arlo includes a 2440mAh rechargeable battery with their cameras that can be charged through the micro-USB port but Blink requires AA batteries and can also accept a charge from solar through its micro-USB port.

There are a number of variables that affect the battery life of the Ring including how much power the solar panel is producing and how much power the Ring is consuming.

Power Production of Solar Panel

Power Consumption of the Ring: This is determined by amount of motion which activates the sensors and video within the motion zones you set in the Ring app. More movement and a larger motion radius requires more power.

Here are some performance specs we discovered through testing with a combination of our bench DC Power Supply and 3.5 watt solar panel:

The Ring Stick Up Cam will allow an input voltage in the range of 4.2V – 6.0V. It will also accept input currents as low as 5mA and as high as 1A.

The table below indicates the charge rate at different solar intensities. The various solar intensities were replicated by angling a 3.5 watt solar panel away from the sun in conjunction with a solar intensity meter until the desired SI was achieved.

Note: No issues were discovered when replicating clouds or shade on the panel, causing the power to drop to almost 0 watts, and then recovering to full sun.

Ring Solar Charge Rate from 3.5 Watt Panel

Solar Intensity (w/m^2)

Volts

Amps

Power (watts)

70

4.15

0

0

75

4.15

0.01

0.0415

200

4.45

0.13

0.5785

400

4.67

0.24

1.1208

600

4.39

0.36

1.5804

800

4.40

0.48

2.112

960

4.52

0.56

2.5312

The table above indicates power production in just about full sun (960 w/m^2) from the 3.5 watt panel is actually 2.5312 watts. The results of our test revealed that our 3.5 watt panel will charge a completely flat Ring Stick Up Cam battery in about 12 hours of full, direct sun.

We also tested different sized panels to determine whether or not a larger panel may suit a lower light environment better than a smaller panel.

Power Inputs from Various Panel Sizes

Panel Size

Solar Intensity (w/m^2)

Temperature (F)

Volts

Amps

Power (watts)

2 Watt

875

72

4.47

0.36

1.61

3.5 Watt

940

72

4.53

0.55

2.49

6 Watt

940

72

4.89

0.91

4.45

9 Watt

940

72

6.02

1.02

6.14

From the data above, we found that our 3.5 watt panel produces 65% more power than the 2 watt panel, offering better charging performance in low light conditions. If you’ll be placing your camera and solar panel in an area that gets very little light during the day, is in indirect sun, or there is some shade, we might recommend opting for an even larger 6 watt panel, which produces 55% more power than the 3.5 watt.

Physically, our panels differ from Ring’s solar panel in that they look sharp, are compact, lighter in weight, produce more power, and are manufactured with a high-quality, water-proof urethane coating that will keep them performing well outside for 10 years.

Get Your Own Voltaic Ring Solar Charger

We recommend our 3.5 Watt solar panel for charging at your home. To get yourself set up here’s what you’ll need:

]]>https://www.voltaicsystems.com/blog/ring-cam-choosing-a-better-solar-panel/feed/2Monitoring Illegal Logging and Poaching with Solarhttps://www.voltaicsystems.com/blog/monitoring-illegal-logging-poaching-solar/
https://www.voltaicsystems.com/blog/monitoring-illegal-logging-poaching-solar/#respondTue, 19 Dec 2017 18:25:52 +0000https://www.voltaicsystems.com/blog/?p=9359Rainforest Connection has been working to monitor and detect illegal deforestation and poaching. Their thesis is that if “you can protect the trees, you end up protecting everything else.” They use old cell phones to listen and monitor for different sounds. A recent National Geographic Article stated that the phones can “detect the sounds of […]

]]>Rainforest Connection has been working to monitor and detect illegal deforestation and poaching. Their thesis is that if “you can protect the trees, you end up protecting everything else.”

They use old cell phones to listen and monitor for different sounds. A recent National Geographic Article stated that the phones can “detect the sounds of chainsaws nearly a mile away.” Once logging is detected, their system sends a text message to local forest rangers or indigenous tribes so they can intervene.

Over the last two years, Rainforest Connection has been using our waterproof solar panels to power the audio monitors. The challenge with rainforests is that the dense canopy limits the amount of direct light hitting the solar panels.

Rainforest Connection mounts the panels high in the canopy, but individual solar panels may be partially shaded, dropping the power output of the system. The solution to date is to increase the total amount of power and use multiple panels to catch the sun at different times during the day.

Learn more about Rainforest Connection and all the great work they are doing on their site.

]]>https://www.voltaicsystems.com/blog/monitoring-illegal-logging-poaching-solar/feed/0Can Your Panel Charge My Battery Pack?https://www.voltaicsystems.com/blog/can-panel-charge-battery-pack/
https://www.voltaicsystems.com/blog/can-panel-charge-battery-pack/#respondSun, 19 Nov 2017 17:20:40 +0000https://www.voltaicsystems.com/blog/?p=9343Maybe, but probably not that well. Charging battery packs from a solar panel isn’t as straightforward as you think – even if the solar panel output is regulated. We recently tested 10 different battery packs and 6 had serious problems with solar charging, while 2 more had minor problems. Only 2 performed well enough that […]

Charging battery packs from a solar panel isn’t as straightforward as you think – even if the solar panel output is regulated. We recently tested 10 different battery packs and 6 had serious problems with solar charging, while 2 more had minor problems. Only 2 performed well enough that you probably wouldn’t be able to notice any significant issues. If you pair your battery pack (Anker and Mophie are two common choices) with our solar panels, what will happen?

Common Issues Charging Battery Packs from Solar

Minimum Charge Rate: The battery will not accept any input power if what’s coming from the panel is less than a pre-determined limit (such as when the panel is too small or in non-ideal conditions)

Maximum Charge Rate: If the maximum charge rate of the battery is set too low (typically 1A), potential power from the panel can be wasted

No Cloud Recovery: If the solar panel is shaded by a cloud or shadow, even after the cloud goes away the battery will not resume charging at the fastest available rate

Low Voltage: The battery will pull the voltage of the solar panel down so low that extra power is unnecessarily lost

Simultaneous Charge and Discharge: Many batteries cannot charge and discharge at the same time at a fast rate, and others cannot do this at all

Performance Testing Power Banks With Solar

The good news is that there are some simple tests you can do on your own to see how well your battery and solar panel work together. You will need a USB multimeter. There are lots on Amazon to choose from.

Step 1. Charge Rate

Go outside on a sunny, clear day. Connect the panel to the USB multimeter and the USB multimeter to the battery. You should see 70-80% of the rated power of the panel flowing into the battery (Volts x Amps = Power).

Is the battery charging at all? If so, angle the panel away from the sun. You should see the power decrease, but not straight to zero. The battery pack should be able to smoothly accept any small input amps, even as low as 20mA.

Here are two batteries charging from our Arc 10W in similar conditions (slight haze, sun low in the clouds), but with very different amounts of power.

Beware the LED charge indicators: Most battery packs on the market will turn on their LED charge indicators to imply the battery is charging even if no amps are flowing into the battery as long as a positive voltage is detected from the solar panel. This is why you need a multimeter to see exactly how many amps are flowing into the battery.

Step 2. Charge Recovery

Point the panel at the sun and observe the charge rate (volts and mA). Angle the panel away from the sun or cast a shadow over the panel to see the output power drop (potentially all the way to zero amps while an input voltage from the panel is still available). Remove shadow or point the panel back at the sun and observe if the charge rate increases to the previous rate.

Step 3. Charge & Discharge

Put the USB multimeter between the battery and your phone or tablet to observe how fast your devices normally charge (will most likely be 1-2A). Do this test when your phone or tablet’s battery is less than 90% full, that way it will charge at it’s maximum charge rate.

Connect the solar panel to the battery. Confirm that the charge rate to your device stays the same. The charge rate to your device might decrease to a slow rate, cycle between a fast rate and a slow rate, or stop charging altogether. Unplug and replug the solar panel cable while your device is charging from the battery, and unplug and replug your device while the battery is charging from the solar panel in case there is any difference in charge rate between those two scenarios.

Additionally, you can place the multimeter between the solar panel and the battery while the battery is charging your device. Some batteries will limit the output power to your device while other batteries will limit the input power from the solar panel, so it’s important to test both.

If your battery fails any of these tests, it will not be a reliable solution for you on your next trip. You can experiment with other batteries on Amazon, or purchase on of our solar batteries that we’ve specifically designed for charging from a solar panel.